1. Field of the Invention
The present invention relates to a rare earth magnet and a production method therefor.
2. Related Background Art
The rare earth magnets containing rare earth elements, although having high magnetism, are rather poor in corrosion resistance as they contain a readily oxidizable rare earth element as a principal ingredient. Therefore, the rare earth magnets are mostly provided with a protective layer formed by resin coating or plating on the surface of the magnet body containing a rare earth element. Recently, demand is also increasing for the technique that enables formation of a protective layer that can exhibit corrosion resistance higher than a certain level more easily and at a lower cost than conventional techniques, for the cases where corrosion resistance of a magnet body itself has been improved or where there is no need for such high corrosion resistance as required in the past.
As an example of the rare earth magnets having such a protective layer, there is known an anti-corrosive rare earth magnet having a flaky fine powder/alkali silicate composite film obtained by heating a film formed from a treatment solution containing flaky fine powder of a specific metal and an alkali silicate (See Japanese Patent Laid-Open No. 2006-49864).